Originally posted by BarryE Obligatory Rule: Give reasons/background and if possible a web reference
Oops, I didn't pay attention to this one.
1. Tripod: in addition to making it feasible to shoot at longer shutter speeds, which is necessary for much of the photography I do, it also allows and/or encourages a more deliberate approach to composition. (And for my 4x5 it is obligatory.)
2. Polarizing filter: cuts reflections and improves contrast and saturation for a result that is simply not possible by other means.
3. Notebook: this is my "unusual" one; I really only use it for film work. I prefer it to an electronic device for note taking, both for reliability and also for matching the more mechanical nature of my film workflow. (I also use it as a reference for various things: reciprocity failure tables, filter factors, etc.)
BTW, I too think that L-brackets are great, but they're not much use without a tripod.